One feature of a mobile device is the device's operational use time, i.e. the duration for which the device may be continuously used as a function of the device's stored energy (e.g. battery) capacity. Most mobile devices are designed to automatically search or poll for signals from various wireless communication networks (e.g. cellular phone, Wi-Fi, 3G). Searching for network signals uses electrical power. If the mobile device is in a location for an extended period of time, where the network signal strength is low or non-existent (commonly referred to as ‘dead zones’), the device may perform continuous polling. Continuous polling for network signals uses excessive electrical power and can reduce a device's operational use time.
To prevent premature battery drain from excessive signal searching, some mobile devices permit users to manually place the device in a mode such as ‘airplane mode’ or ‘off mode’. This prevents the device from continuously searching for a signal when the user has reason to believe that network communication is not possible (e.g. when the user is in a remote area, a building, on an airplane, or on a subway). This form of manual user intervention is cumbersome, inefficient, and inconvenient. Furthermore, this method of user intervention relies on the user to know the user is in a dead zone (e.g., an area with no detectable signal). It may not always be apparent to the user that the device is operating in a dead zone, for example if the user is moving from one location to another and not closely monitoring the network signal strength being reported by the device.